The present invention relates to apparatus for crimping the ferrules of electrical terminals and more particularly to a portable pneumatically operated crimping press for crimping terminals carried by a tape.
Electrical terminals of the type having a ferrule or barrel from which extends a ring, fork, blade . . . etc. have been used in electrical wiring for many years. The ferrule is crimped about the stripped end of an insulated wire and initially plier-like hand tools were used for deforming the ferrule. This method of termination proved extremely time consuming, and, if the ferrule was misaligned with respect to the tool jaws, often yielded terminations which were unacceptable.
Crimping presses subsequently were offered which included a pair of die members relatively movable between an open position and a crimping position. These presses required the terminals to be loaded individually and the operator to hold a wire in the ferrule as operation of the press was initiated, for example, by actuation of a foot treadle. While such presses offered faster termination than hand tools, the manual loading of terminals, besides being tedious and a safety hazard to the operator, again often resulted in terminals misaligned with the die members and attendant unsatisfactory terminations.
To overcome these deficiencies, crimping presses were proposed for use with terminals carried on a tape or belt advanced by a sprocket wheel or the like to bring successive terminals into registration with the crimping dies after crimping of the downstream terminal had been completed and it had been removed from between the dies. One such press included a plurality of air cylinders for moving the die members from their crimping position to a full open position and thereafter to a clamping or holding position wherein the next terminal to be crimped was concurrently engaged by both die members prior to insertion of the wire. The inclusion of the clamping position in the cycle of operation offers a safety advantage because when the operator inserts the wire, the die members are sufficiently close together to prevent the operator inadvertently positioning a finger between them.
The air cylinders also function to advance the tape as the die members are moved from their full open position to their clamping position. This creates a race condition between the tape and the die members because if the die members reach their clamping position prior to completion of tape advance, the die members will interfere with the next terminal and prevent its moving into registration with the die pockets. This prior art press offers only a single tape advance length thus requiring the terminals carried by the tape to be on the same centers without regard to their size. Accordingly, a tape carrying small terminals will require relatively large spaces between adjacent terminals. Reference may be made to U.S. Pat. Nos. 3,037,545 and 3,423,815.